<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>subapp1</title>
    <style>
        body {
            color: red;
        }
    </style>
    <link rel="stylesheet" href="/test.css">
</head>

<body>
    <div>subapp1</div>
</body>
<script src="/index.js"></script>
<script>
    alert('subapp1')
</script>

</html>